Heating apparatus



Oct. 25, 1955 R. T. scHoERNER HEATING APPARATUS Filed OCb. 2, 1951 nited States Patent @Hice 2,721,706 .Patented Oct. 25, i955 HEATING APPARATUS Rudolph T. Schoerner, Oaklawn, R. I., assignor to Taco Heaters, Incorporated, Providence, R. I., a corporation of New York Application October 2, 1951, Serial No. 249,338

` 6 Claims. (Cl. 237-8) This invention relates to hot water heating apparatus and systems, particularly one useful for household heating, although it can be applied to other uses.

Various arrangements have been proposed `for controlling a hot water heating system including a boiler, automatic firing device, circulating pump, and radiators or heat radiating devices. One of the ditiiculties hasV been in arranging a combination so that it will furnish a low level heat to the radiating device in a space at the proper point or temperature. If the temperature in the space falls below a predetermined temperature so that the low level heat is insuicient, it is then necessary to furnish a higher lever heat to the area.

In prior devices having circulators, valves have been placed in the boiler outlet arranged so that they would be open when a thermostatic means in the room or space being controlled called for heat, the circulator and firing device also being started at the same time. None of these arrangements has been entirely satisfactory, especially where domestic water was heated, because it was possible for the temperature of the water in the radiators to drop to a very low point. Then, when the thermostat called for heat, the circulator would take most of the hot water out of the boiler and the cold water from the radiators would be fed into the boiler. If domestic hot water was being drawn at this time, none would be available because the boiler water would be so cold that there would be insuiicient heat transfer to the domestic hot water heat exchanger. Also, it was possible for the air in the room to stratify when the temperature of the water in the radiators was allowed to drop to a low point and this would create a chilly feeling adjacent the floor level.

One of the objects of the invention is to provide a heating system arranged so that a low level of heat can be supplied to the radiating devices prior to the time the room thermostat calls for a high level of heat.

Another object of the invention is to provide an improved control arrangement so that boilerI water will not be fed in quantities into the system until the Water is at a predetermined high level temperature.

Still a further object of the invention is to provide an improved zone control arrangement.

In one aspect of the invention, the radiating devices can be connected to a circulating system which includes the boiler, there being a thermostatically operable valve in the boiler outlet pipe, said thermostatic valve being responsive to water temperature in the supply pipe and arranged so that it will not open until the water has reached a predetermined temperature. The boiler can be heated by a conventional heat generating unit. Also, there can be a domestic water heat exchanger inserted in a line connecting the boiler outlet and return pipes therein. Conventional high and low limit immersion thermostats can be used in conjunction with the boiler.

The aforementioned thermostatic valve may have a relatively small bleed hole or can have a byf-pass line arranged so that water can ow from the boiler supply pipe to the radiator supply pipe at all times when the circulator is operating even though the thermostatic valve is closed.

Circulation in the system can be effectuated by a circulating pump. When the circulator is operating, the low limit boiler immersion thermostat will maintain the boiler water at or above a predetermined temperature. After the burner is started, the high limit immersion or safety thermostat will prevent the boiler temperature from rising above a predetermined higher temperature.

The circulating pump can be connected to a circulator thermostatic switch arranged so that it will start the pump or circulator operating when a small amount of heat or heat at a low level is required in the radiating system and before the room thermostat calls for heat at a high level. Said circulator, or space, thermostatic switch for furnishing low level or small amount of heat may be responsive to room temperature in one aspect of the invention or may be responsive to outdoor temperature in another aspect of the invention. In either instance, the circulator will be started when there is a requirement for low level heat, water circulating through the radiators because of the bleed or by-pass through the boiler outlet thermostatic valve, even though the valve is closed. In such an arrangement, the circulator will run substantially continuously at the time low level heat is required or called for, and thus there will be a small amount of hot water fed to the radiators through the bleed hole or by-pass line. If the outdoor circulator thermostat becomes satisfied, or the room circulator thermostat becomes satisfied, the circulator will be shut off and the only circulation will be through the domestic hot water heating arrangement. v

The burner motor can be connected to a room high level heat thermostat in such a manner that when room temperature decreases to a predetermined point, the burner will be actuated to furnish heat at a high level or the full amount capable of being produced by the system. When an outside thermostat is used for controlling the circulator, the burner thermostat can also be connected so that it will operate the circulator Whenever the burner runs even though the outside thermostat is satisfied.

With the circulator running, when the temperature in the room falls to the setting of the high level heat thermostat, the burner motor will be activated. This will raise the boiler water temperature to a point which Will open the boiler outlet thermostatic valve and thereby permit greater amounts of hot Water to be furnished to the system.

In a further aspect of the invention, when the circulator thermostat is in the room, a plurality of pairs of room (high level heat) and circulator (low level heat) thermostats can be provided together with a plurality of circulators to heat various zones. In this instance, when the temperature in any zone falls to a predetermined point, its circulator will be started to furnish low level heat to the zone. Then, if the temperature in any one or more zones falls to the setting of its thermostat, or thermostats, controlling the burner motor, the burner motor also will be activated furnishing high level heat. High level heat then will be available for all of the zones.

These and other objects, advantages, and features of the invention will become apparent from the following description and drawings.

In the drawings:

Figure l is a diagrammatic illustration of one form of the invention.

Figure 2 is an enlarged sectional view of one type of valve which can be used in the boiler outlet.

Figure 3 is a schematic view of another form of the invention.

Figure 4 is a schematic view of an additional zone which can be added to Figure 3.

Boiler may be of any conventional type for hot water, said heating boiler having a suitable oil burner or automatic heat generating unit 11. Boiler outlet pipe 12 is connected to the thermostatic valve 13, one form of said valve being illustrated in Figure 2.

The thermostatic valve 13 has a thermostat 14 arranged to operate the valve plate 15. Valve plate 15 may have a bleed hole or by-pass arrangement 16 therein which Will pass a restricted amount of water through said plate when it is closed, the water passing to the radiator supply pipe 17 (Figure l).

Radiator supply pipe 17 can be connected through a conventional flow check valve 18 with radiators or heat radiating devices 19, 19. The return from the radiators can be through a conventional venturi fitting 20 leading to the return line 21. Return line 21 is connected to a circulator pump 22, the outlet of the circulator pump being connected to the boiler return line 23. A domestic water heater 24 can be connected by pipes 25 and 26 to the boiler outlet pipe 12 and boiler return connection 26 respectively, a flow inducing valve 27 in the return line to the boiler being employed if desired. The cold water supply to the domestic water heater 24 may be through line 28 and line 29 to suitable coils in heater 24. Domestic water outlet pipe 30 is connected to a thermostatic tempering valve 31 which will mix cold water from connection 32 with the hot water coming from connection 30 so as to control its temperature as it is fed to the domestic water line 33. Drains 34, 35 and 36 may be employed if desired. Also, suitable shut-off valves 37, 38, 39, 40, 41, 42, 43, 44 can be provided as needed. If desired, valve 39 can be opened to permit recirculation of water through the bypass.

The boiler may be supplied with cold water from cold water supply pipe 45 through reducing valve 46 and line 47. A conventional relief valve 48 can be connected to the cold water supply line 47. The circulating pump motor 49 is connected to the thermostat 50, said thermostat in this form of the invention being an outside thermostat or one responsive to the ambient temperature of the house. The boiler may have conventional high and low temperature immersion thermostats H, L, controlling the same.

The burner motor 11 can be controlled by an indoor or room thermostat 51. In this aspect of the invention, when outdoor temperature falls to a predetermined point and low level heat is required, the circulating pump 22 will be actuated and circulate water around the system, water passing through the bleed hole 16 in thermostatic valve 13 to the radiators and through the return line to the boiler. As will be described hereafter, a room thermostat can be used to control the circulator in place of the outdoor thermostat when low level heat is required. The outdoor thermostat 50 is set so that low level heat will be supplied to the radiators at a predetermined setting of said thermostat, said thermostat being arranged to start the circulator when an outside temperature is reached which is lower than that at which the setting of the inside room starts the burner in response to room temperature. Thus, when low level heat is required because of outside temperature conditions, the circulator will start. When the room temperature drops to a point where room thermostat 51 calls for heat at high level, the burner 11 will be turned on by said thermostat. As soon as the water in the boiler and adjacent to thermostatic valve 13 reaches the setting of said valve, valve plate 15 will open and permit hot water in large quantities to ow to the radiators so as to furnish a high level heat to the zone. It is thus seen that the circulating pump will be operating continuously when there is a demand for low level heat caused by slight lowering of the outside temperature.

As an example, the thermostatic valve 13 may be arranged so that it opens when the temperature of the Water reaches 185 F. and will be closed when the water is lowered to 175 F. If, for any reason, the temperature in the boiler should rise, for example, to 210 F. the high limit control of the boiler will shut off the burner.

As a further example, the outside thermostat may be set at 45 so that it will `sftart the circulator when the outside temperature reaches this point. The size of the bleed hole in the thermostatic valve must be chosen to suit the amount of water desired to be circulated through the system when the thermostatic valve is closed. A connection 49A can be provided to cause operation of the circulator whenever burner 11 is operating.

In another aspect of the invention, the circulator thermostat can be placed in the space to be heated and set so that it will be actuated to operate the circulator when the temperature of the space drops to a point above that for which the thermostat for operating the burner is closed. This is illustrated diagrammatically in Figure 3 wherein boiler 60 has burner motor 61 and boiler outlet pipe 62 connected to the thermostatic valve 63. Thermostatic valve 63 is similar to valve 13 of Figure 2 and has a bleed hole or by-pass arrangement. Domestic water heater 64 is connected by pipes 65 and 66 across boiler 60. The radiating system supply line 67 is connected to the return line 68 and pump 69 as in the previously described arrangement of Figure l. The circulator thermostatic switch means 70 is connected to one side of power line 71 through line 72 and line 73. When the switch blade of 70 closes, it connects the power line 71 through lines 72, 73 and 74 to the circulator motor 69, said circulator motor being connected by line 75 with power supply line 76. It is to be understood that suitable relays, transformers, and voltages can be employed in the various circuits.

The burner motor thermostatic switch 77 is connected to power supply line 71 through line 72 and line 78. The switch blade of 77 is connected through line 79 to the burner motor 61. Thus, when the room or space ternperature drops a predetermined amount so that a low level source of heat is required, switch 70 tirst will close and start the circulator operating and thus circulate a restricted amount of water through the system. Then, if the room or burner thermostat 77 also closes, the burner will start and the thermostatic valve 63 will open when the temperature of the supply water reaches a predetermined point.

The arrangement of Figure 3 also can be used in conjunction with a plurality of other circulator and zone or space thermostats. As an example thereof, the space thermostatic combination (Figure 4) can be placed in zone 2, connected wires and pipes being indicated by like letters. The circulator for zone 2 is indicated at 101 and is controlled by the circulator switch 102. The burner switch 103 is arranged so that it can control burner motor 61.

If, for example, zone 2 thermostat 102 closes in response for a demand for low level heat, circulator 101 will operate and will furnish low level heat to the radiating device in said zone, the bleed hole in the thermostatic valve 63 permitting ow of water thereto. In the event thermostat 103 then is closed, the burner will be started. In this instance, of course, higher temperature water will be furnished to both of the zones providing both of the circulators are operating. Pipes C-C can be connected together and pipe D leading from pump 101 can be connected directly to the boiler 60.

It is to be understood that various details of construction and arrangement can be made without departing from the spirit of the invention except as defined in the appended claims.

What is claimed is:

l. In a heating system, the combination including a hot water boiler, a heat generating unit for said boiler, a supply and return pipe adapted to connect said boiler with a heat radiating system, a water circulator for said heat radiating system, a thermostatic control connected to said circulator to actuate the same continuously when any heat is required in said system, a water temperature actuated thermostatic valve in said supply line leading from the boiler to said radiating system, restricted water flow means connecting the inlet and outlet of said thermostatic valve for passing a limited amount of water therethrough, said valve remaining closed until a predetermined water temperature is reached, and a room thermostatic control connected to said heat generating unit actuating the same upon high level demand for heat by the space to be heated, said generating unit raising the temperature of water to open said thermostatic valve and to supply hot Water to the radiating system.

2. In a heating system, the combination including a hot water boiler, a heat generating unit for said boiler, a supply and return pipe adapted to connect said boiler with a heat radiating system, a water circulator for said heat radiating system, an outside temperature responsive control connected to said circulator to actuate the same continuously when the outside temperature falls below a predetermined point, a Water temperature actuated thermostatic valve in said supply line leading from the boiler to said radiating system, restricted water flow means connecting the inlet and outlet of said thermostatic valve for passing a limited amount of water therethrough, said valve remaining closed until a predetermined water temperature is reached, and a room thermostatic control connected to said heat generating unit actuating the same upon high level demand for heat by the space to be heated, said generating unit raising the temperature of the Water to open said thermostatic valve and to supply hot water to the radiating system.

3. In a heating system, the combination including a hot water boiler, a heat generating unit for said boiler, a supply and return pipe adapted to connect said boiler with a heat radiating system, a Water circulator for said heat radiating system, a space thermostat connected to said circulator actuating the same continuously when the space temperature falls below a predetermined amount which requires low level heat, a water temperature actuated thermostatic valve in said supply line leading from the boiler to said radiating system, restricted water flow means connecting the inlet and outlet of said thermostatic valve for passing a limited amount of water therethrough, said valve remaining closed until a predetermined water temperature is reached, and a room thermostatic control connected to said heat generating unit actuating the same upon high level demand for heat by the space to be heated at a temperature below said space thermostat, said generating unit raising the temperature of the water to open the thermostatic valve and supply hot water to the radiating system.

4. In a heating system, the combination including a hot water boiler, a heat generating unit for said boiler, a supply and return pipe adapted to connect said boiler with a heat radiating system, a water circulator for said heat radiating system, a thermostatic control connected to said circulator to actuate the same continuously when any heat is required in said system, a water temperature actuated thermostatic valve in said supply line leading from the boiler to said radiating system, restricted water flow means connecting the inlet and outlet of said thermostatic valve for passing a limited amount of water thereby, said valve remaining closed until a predetermined water temperature is reached, a domestic water heating means connected between the outlet of said boiler before said thermostatic valve and the return to said boiler, and a room thermostatic control connected to said heat generating unit actuating the same upon high level demand for heat by the space to be heated, said generating unit raising the temperature of the Water to open the thermostatic valve and to supply hot water to the radiating system.

5. In a heating system, the combination including a hot Water boiler, a heat generating unit for said boiler, a supply and return pipe adapted to connect said boiler with a plurality of heat radiating systems for a plurality of spaces to be heated, a plurality of water circulators for said heat radiating systems, space thermostats connected to their respective circulators actuating the same continuously when the space temperature concerned falls below a predetermined amount which requires low level heat, a water temperature actuated thermostatic valve in said supply line leading from the boiler to said radiating systems, restricted water llow means connecting the inlet and outlet of said thermostatic valve for passing a limited amount of water therethrough, said valve remaining closed until a predetermined water temperature is reached, and a plurality of room thermostatic controls connected to said heat generating unit actuating the same upon high level demand for heat by the particular space to be heated at a temperature below the corresponding space thermostat in the space involved, said generating unit raising the temperature of the Water to open the thermostatic valve and supply hot water to the radiating systems.

6. In a heating system, the combination including a hot water boiler, a heat generating unit for said boiler, a supply and return pipe adapted to connect said boiler with a heat radiating system, a water circulator for said heat radiating system, a thermostatic control connected to said circulator to actuate the same continuously when any heat is required in said system, a water temperature actuated thermostatic valve in said supply line leading from the boiler to said radiating system, said valve having a bleed hole means connecting the inlet and outlet of said thermostatic valve for passing a limited amount of water therethrough, said valve remaining closed until a predetermined Water temperature is reached, and a room thermostatic control connected to said heat generating unit actuating the same upon high level demand for heat by the space to be heated, said generating unit raising the temperature of the water to open the thermostatic valve and to supply hot water to the radiating system.

References Cited in the le of this patent UNITED STATES PATENTS 2,065,481 Thuhnan Dec. 22, 1936 2,067,629 Flagg Jan. 12, 1937 2,162,337 Kriechbaum June 13, 1939 2,194,805 Moore Mar. 26, 1940 2,481,297 Eggert Sept. 6, 1949 2,539,469 Powers Jan. 30, 1951 

